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/*
* Copyright (C) 2012 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef ScrollingConstraints_h
#define ScrollingConstraints_h
#include "FloatRect.h"
namespace WebCore {
// ViewportConstraints classes encapsulate data and logic required to reposition elements whose layout
// depends on the viewport rect (positions fixed and sticky), when scrolling and zooming.
class ViewportConstraints {
public:
enum ConstraintType {
FixedPositionConstaint,
StickyPositionConstraint
};
enum AnchorEdgeFlags {
AnchorEdgeLeft = 1 << 0,
AnchorEdgeRight = 1 << 1,
AnchorEdgeTop = 1 << 2,
AnchorEdgeBottom = 1 << 3
};
typedef unsigned AnchorEdges;
ViewportConstraints(const ViewportConstraints& other)
: m_alignmentOffset(other.m_alignmentOffset)
, m_anchorEdges(other.m_anchorEdges)
{ }
virtual ~ViewportConstraints() { }
virtual ConstraintType constraintType() const = 0;
AnchorEdges anchorEdges() const { return m_anchorEdges; }
bool hasAnchorEdge(AnchorEdgeFlags flag) const { return m_anchorEdges & flag; }
void addAnchorEdge(AnchorEdgeFlags edgeFlag) { m_anchorEdges |= edgeFlag; }
void setAnchorEdges(AnchorEdges edges) { m_anchorEdges = edges; }
FloatSize alignmentOffset() const { return m_alignmentOffset; }
void setAlignmentOffset(const FloatSize& offset) { m_alignmentOffset = offset; }
protected:
ViewportConstraints()
: m_anchorEdges(0)
{ }
FloatSize m_alignmentOffset;
AnchorEdges m_anchorEdges;
};
class FixedPositionViewportConstraints : public ViewportConstraints {
public:
FixedPositionViewportConstraints()
: ViewportConstraints()
{ }
FixedPositionViewportConstraints(const FixedPositionViewportConstraints& other)
: ViewportConstraints(other)
, m_viewportRectAtLastLayout(other.m_viewportRectAtLastLayout)
, m_layerPositionAtLastLayout(other.m_layerPositionAtLastLayout)
{ }
FloatPoint layerPositionForViewportRect(const FloatRect& viewportRect) const;
const FloatRect& viewportRectAtLastLayout() const { return m_viewportRectAtLastLayout; }
void setViewportRectAtLastLayout(const FloatRect& rect) { m_viewportRectAtLastLayout = rect; }
const FloatPoint& layerPositionAtLastLayout() const { return m_layerPositionAtLastLayout; }
void setLayerPositionAtLastLayout(const FloatPoint& point) { m_layerPositionAtLastLayout = point; }
bool operator==(const FixedPositionViewportConstraints& other) const
{
return m_alignmentOffset == other.m_alignmentOffset
&& m_anchorEdges == other.m_anchorEdges
&& m_viewportRectAtLastLayout == other.m_viewportRectAtLastLayout
&& m_layerPositionAtLastLayout == other.m_layerPositionAtLastLayout;
}
bool operator!=(const FixedPositionViewportConstraints& other) const { return !(*this == other); }
private:
virtual ConstraintType constraintType() const OVERRIDE { return FixedPositionConstaint; };
FloatRect m_viewportRectAtLastLayout;
FloatPoint m_layerPositionAtLastLayout;
};
class StickyPositionViewportConstraints : public ViewportConstraints {
public:
StickyPositionViewportConstraints()
: m_leftOffset(0)
, m_rightOffset(0)
, m_topOffset(0)
, m_bottomOffset(0)
{ }
StickyPositionViewportConstraints(const StickyPositionViewportConstraints& other)
: ViewportConstraints(other)
, m_leftOffset(other.m_leftOffset)
, m_rightOffset(other.m_rightOffset)
, m_topOffset(other.m_topOffset)
, m_bottomOffset(other.m_bottomOffset)
, m_constrainingRectAtLastLayout(other.m_constrainingRectAtLastLayout)
, m_containingBlockRect(other.m_containingBlockRect)
, m_stickyBoxRect(other.m_stickyBoxRect)
, m_stickyOffsetAtLastLayout(other.m_stickyOffsetAtLastLayout)
, m_layerPositionAtLastLayout(other.m_layerPositionAtLastLayout)
{ }
FloatSize computeStickyOffset(const FloatRect& constrainingRect) const;
const FloatSize stickyOffsetAtLastLayout() const { return m_stickyOffsetAtLastLayout; }
void setStickyOffsetAtLastLayout(const FloatSize& offset) { m_stickyOffsetAtLastLayout = offset; }
FloatPoint layerPositionForConstrainingRect(const FloatRect& constrainingRect) const;
const FloatPoint& layerPositionAtLastLayout() const { return m_layerPositionAtLastLayout; }
void setLayerPositionAtLastLayout(const FloatPoint& point) { m_layerPositionAtLastLayout = point; }
float leftOffset() const { return m_leftOffset; }
float rightOffset() const { return m_rightOffset; }
float topOffset() const { return m_topOffset; }
float bottomOffset() const { return m_bottomOffset; }
void setLeftOffset(float offset) { m_leftOffset = offset; }
void setRightOffset(float offset) { m_rightOffset = offset; }
void setTopOffset(float offset) { m_topOffset = offset; }
void setBottomOffset(float offset) { m_bottomOffset = offset; }
// constrainingRectAtLastLayout() is the viewport rect if this sticky object sticks to the viewport, and
// it is the overflow area's scrolled clip rect if this sticky object sticks inside an overflow area.
FloatRect constrainingRectAtLastLayout() const { return m_constrainingRectAtLastLayout; }
void setConstrainingRectAtLastLayout(const FloatRect& rect) { m_constrainingRectAtLastLayout = rect; }
// containingBlockRect() is in the scrolling ancestor's coordinate space.
FloatRect containingBlockRect() const { return m_containingBlockRect; }
void setContainingBlockRect(const FloatRect& rect) { m_containingBlockRect = rect; }
// stickyBoxRect() is in the scrolling ancestor's coordinate space.
FloatRect stickyBoxRect() const { return m_stickyBoxRect; }
void setStickyBoxRect(const FloatRect& rect) { m_stickyBoxRect = rect; }
bool operator==(const StickyPositionViewportConstraints& other) const
{
return m_leftOffset == other.m_leftOffset
&& m_rightOffset == other.m_rightOffset
&& m_topOffset == other.m_topOffset
&& m_bottomOffset == other.m_bottomOffset
&& m_containingBlockRect == other.m_containingBlockRect
&& m_stickyBoxRect == other.m_stickyBoxRect
&& m_stickyOffsetAtLastLayout == other.m_stickyOffsetAtLastLayout
&& m_layerPositionAtLastLayout == other.m_layerPositionAtLastLayout;
}
bool operator!=(const StickyPositionViewportConstraints& other) const { return !(*this == other); }
private:
virtual ConstraintType constraintType() const OVERRIDE { return StickyPositionConstraint; };
float m_leftOffset;
float m_rightOffset;
float m_topOffset;
float m_bottomOffset;
FloatRect m_constrainingRectAtLastLayout;
FloatRect m_containingBlockRect;
FloatRect m_stickyBoxRect;
FloatSize m_stickyOffsetAtLastLayout;
FloatPoint m_layerPositionAtLastLayout;
};
} // namespace WebCore
#endif // ScrollingConstraints_h
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